The use of sample positioning to control defect creation by oxygen plasma in isotopically labelled bilayer graphene membranes

Monolayer and isotopically labelled bilayer graphene membranes were prepared on grids for transmission electron microscopy (TEM).

Influence of the Doping Ion Nature and Content on Defect Creation Processes under the Effect of Ionizing Radiation in Aluminoborosilicate Glasses

Effects of ionizing irradiation on defect creation processes have been studied in rare earth (RE)-doped (RE = Sm, Gd, Eu, Ce, Nd) aluminoborosilicate glass with use of the electron paramagnetic resonance (EPR) and optical spectroscopy. As a function of RE ion nature, we observe that doping significantly influences the nature of the defects produced during irradiation and more specifically the relative proportions between hole and electron defect centers. Strong decrease of defect production efficiency under ionizing radiation independence on both the RE doping content and on the relative stability of the RE different oxidation states is also clearly revealed. The results could be explained by dynamical reversible trapping of the electron-hole pairs produced during irradiation on the different RE charge states as well as by RE segregation and pre-existing defects speciation in ABS glass structure.

Light-induced defect creation processes and light-induced defects in hydrogenated amorphous silicon

We have proposed a model of light-induced defect creation processes and light-induced defects. Recently, important results using pulsed electron-nuclear double resonance (ENDOR) by Fehr et al. [M. Fehr, A. Schnegg, C. Teutloff, R. Bittl, O. Astakhov, F. Finger, B. Rech, K. Lips, Phys. Status Solidi A 207, 552 (2010)] have been reported, so that these results are interpreted on the basis of our model. Fehr et al. have observed ENDOR signals due to hydrogen nuclei distributed around a dangling bond. The ENDOR spectra due to hydrogen nuclei being located with distance of r from the dangling bond have been calculated, taking into accounts the dipolar interaction, and also the Fermi-type contact hyperfine interaction for the H-related dangling bond (HDB) that is a dangling bond having hydrogen at a nearby site. The typical features of the observed ENDOR spectra are that the spectrum has a shoulder at the low frequency side from the natural NMR frequency of hydrogen and it has a dip in the central part. The calculated ENDOR spectrum of HDB exhibits such a shoulder. This is consistent with our model of light-induced defects such as HDB. The ENDOR spectra with various values of r are calculated. In this paper, we also deal with the distant ENDOR precisely, using the theory of distant ENDOR by Lambe et al. [J. Lambe, N. Laurance, K.C. McIrvine, R.W. Terhune, Phys. Rev. 122, 1161 (1961)]. The calculated distant ENDOR spectrum shows a dip in the central part. Concerning the dip, Fehr et al. attribute the dip to be due to the suppression of the matrix ENDOR line (this is called the artifact). Thus, it is not obvious whether the dip is due to such an artifact or the central part of the distant ENDOR spectrum.

Two-dimensional MoS2 nanosheet-modified oxygen defect-rich TiO2 nanoparticles for light emission and photocatalytic applications

MoS2/TiO2 nanohybrids efficiently decompose organic pollutants under sunlight due to the combined effects of defect creation and hetero-junction formation.